The present invention relates generally to the art of toner cartridge recharging. More particularly, it relates to a new and improved toner hopper replacement seal assembly that provides effective and durable toner hopper sealing, is easily removed prior to use of the toner cartridge without damage to gasketing and other essential cartridge components, and which simplifies subsequent recharging of the toner cartridge upon the depletion of toner.
Toner cartridges are well known and are used in laser beam printers, facsimile machines, electrophotographic copying machines, and other such apparatus to form an image on a piece of paper or other suitable image recording media. In such image forming apparatus, a latent image is formed by selectively exposing a rotating photosensitive drum which has been uniformly charged. Toner is then transferred from a toner hopper or tank to the photosensitive drum to form a toner image on the drum. A recording sheet, most commonly paper, is contacted with the drum so that the toner image is transferred to the sheet for viewing. Finally, a wiper blade contacts the drum and removes any excess toner so that another latent image may be formed on the drum.
To prevent the flow of toner from the toner hopper during shipping, handling, and installation of the toner cartridge, a seal member is positioned over the toner discharge opening in covering relation therewith. Typically, the seal member is disposed in sealing engagement with the hopper through use of an adhesive vehicle or the equivalent. A leader is connected to the seal and extends outwardly from the cartridge through a seal removal slot or opening located between the hopper and an associated magnetic roller or housing. Immediately prior to or following insertion of the toner cartridge into an image forming apparatus, the leader is pulled outwardly relative to the cartridge so that, in turn, the seal member itself is pulled away from the toner discharge opening and out of the cartridge. Depending upon the type of cartridge involved, the overall seal assembly may include a gasket member that remains in the cartridge to inhibit toner leakage between the hopper and the interconnected magnetic roller housing.
It is well known to recharge toner cartridges with toner upon the depletion of the toner from the toner supply hopper. In one type of recharging process, the hopper is separated from the magnetic roller housing. The toner discharge opening is then resealed and the hopper refilled with toner. Once reassembled, the toner cartridge is ready for use in an image forming apparatus upon removal of the replacement seal in a like manner to that described above.
Various types of replacement seals are known for resealing the toner discharge opening. One common prior replacement seal comprises a strip of flexible plastic that is positioned over the toner discharge opening and heated in conjunction with the application of pressure so that the seal partially melts and becomes bonded to the toner hopper. While such seals have been found to be effective, the proper positioning, heating, and bonding these seals to the toner hopper is time consuming and requires heating elements and presses which are expensive to build and maintain. Further, the heating elements and presses require trained operators for safe and effective operation. Also, more recent toner cartridge designs and constructions are such that these heat seals are simply unsuitable for hopper resealing applications.
FIGS. 1-3 in the drawings annexed hereto and made a part hereof illustrate another prior replacement seal member A which is adhesively bonded to the toner hopper B in a covering relation with the toner discharge opening C. The seal member A may include a foam or other gasket disposed in surrounding relation to the toner discharge opening. After the seal member A is adhered to the hopper B, a magnetic roller housing D is reconnected to the toner hopper B. A leader E of the seal extends outwardly between the hopper B and the magnetic roller housing D. The magnetic roller housing includes at least first and second foam gaskets F1,F2 to prevent toner leakage between the hopper and the magnetic roller housing after the seal has been removed from the cartridge. As described above, to remove the seal member A prior to use, the leader E is pulled away from the cartridge as indicated by the arrow G (FIG. 3). However, with these prior sealing arrangements, the adhesive H used to bond the seal member A to the hopper B remains at least partially adhered to the seal member itself rather than to the hopper B. As such, and during seal removal as is depicted in FIG. 3, the adhesive H is exposed to the foam gaskets F1,F2. This exposure thus causes the seal member to at least partially adhere to the foam gaskets. Further pulling of the leader E results in the foam gaskets F1,F2 being torn or pulled away from their operative positions thereby rendering them ineffective or certainly less effective in preventing toner leakage.
To combat this problem, one prior adhesive seal is constructed from a fibrous or ribbon-like material that tears very easily in the direction E in which the leader is pulled. In this type of replacement seal, the central portion of the seal member is pulled away from the cartridge while the seal member edges remain adhesively bonded to the hopper. Although this approach adequately prevents the seal member from adhering to the foam gaskets F1,F2, such seals have not been found sufficiently durable. As is illustrated in FIG. 1, ruptures I occur in this type of seal arrangement if the recharged toner cartridge is inadvertently dropped or otherwise roughly handled or mishandled. Also, these seals have been found to be undesirably expensive, and typically include a relatively thick gasket member that may be up to approximately 0.036 inches or more in thickness. This excessive thickness prevents the seal from being used to reseal certain types of cartridges available and used in the marketplace.
Accordingly, it has been considered desirable to develop a replacement seal assembly for sealing a toner hopper discharge opening that is easily installed without complex equipment, is durable, and does not damage foam gaskets or other components of the cartridge as the seal member is pulled from the cartridge.
The subject invention is deemed to meet the foregoing needs and others, and provide a new and improved replacement seal assembly for a toner cartridge that provides better and more advantageous overall results.